[Sanskrit Avatāra “descent”, from avatarati “he descends”, from ava- “away” + tarati “he crosses over”] The incarnation of the Word; the descent or crossing-over of the Universal Christ from the plane of Spirit to the plane of Matter.
The Encyclopedia of Eastern Philosophy and Religion defines avatar as
an incarnation of divine consciousness on earth. An avatara is born not as the result of karma (as are ordinary human beings) but from an act of free will, and such a one is conscious of his divine mission throughout his life. He appears [in time of trouble] in order to establish new pathways for religious realization and to adapt them to the age in which he is born.
The avatar of an age
The avatar of an age is the Christ, the incarnation of the Son of God (Vishnu), the Second Person of the Trinity. The avatar, with his divine complement, Shakti, or twin flame, “outpictures” and “outplays” in consciousness and in the four lower bodies the archetypal pattern of the Father-Mother God for the evolution of souls in a two-thousand-year cycle.
The principal avatars of an age are two in number—the masculine and feminine prototypes who embody and show by their example the path of initiation designated by the solar hierarchies responsible for the lifewaves moving toward the center of the Cosmic Christ through the Open Door (the Teacher and Teaching) of that two-thousand-year dispensation. According to mankind’s karma, the evolutionary status quo of the children of God (their soul progress or lack of it in previous dispensations), and the requirements of the Logos, the Manus may designate numerous Christed ones—those endued with an extraordinary light—to go forth as world teachers and wayshowers.
The Christed ones demonstrate in a given epoch the Law of the Logos, stepped down through the Manu(s) and the avatar(s) until it is made flesh through their own Word and Work—to be ultimately victorious in its fulfillment in all souls of light sent forth to conquer time and space in that era.
The coming of the avatar
Hermes Trismegistus has said:
Earth has not been without the avatara. But this is an hour of great transition and great requirement where those who have been the recipients time and again, such as you, of the presence and the peace, the harmony and the enlightenment of such as we, must now receive the torch to be and to become all that you have witnessed of the Adam Kadmon for many hundreds of thousands of years upon earth. Thus no new avatara may descend except there be the magnet upon earth of the inner alchemy of the Spirit in those who are the ancient souls who have returned again and again.
It is time for the turning of the great alchemy of Life. It is time for the reflecting pools of many souls to reflect the fullness of the Spirit. It is time for the singing of the song of Hermes Trismegistus by all of the powers within, all of the initiatic symbols, all of the reinforcement of the will. By thy will, sing the hymn of the Sun and be the Son! By understanding, and not perverseness or ignorance, affirm the law of regenerative being and know that unless there be regeneration in the here and now, there cannot be regeneration in the hereafter.
The avatar of the Aquarian age
Saint Germain has said:
And therefore I AM Saint Germain, Messenger of Sanat Kumara unto the Aquarian age. Therefore I AM Saint Germain, avatara of this age, initiating all people of Light in the way of transmutation, in the way of the sacred fires of the Holy Spirit that are indeed for the judgment and the all-consuming fire that shall truly cause the greatest changes in the history of this planet that have been known since her inception in the Mind of God!
Mark L. Prophet and Elizabeth Clare Prophet, Saint Germain On Alchemy: Formulas for Self-Transformation.
Pearls of Wisdom, vol. 38, no. 6, February 5, 1995, endnote.